Titan, lost communication with tour operators on Sunday while about 435 miles south of St John's, Newfoundland, during a voyage to the Titanic off the coast of Canada. The last 'ping' of its homing device was heard on Sunday afternoon when it was located directly above the Titanic.
A countdown has now begun with the vital oxygen supply expected to run out at 12.08pm GMT (7.08am EST) with a 'miracle' now needed to find it in time as banging every 30 minutes is still being heard from the depths but has not been located.
Disclaimer: This is part of a live update that can be followed here.